If you work with medical imaging files, this site can help you. Looking for a free DICOM viewer, DICOM converter, or PACS client? You'll find them here. idoimaging.com tracks free medical imaging applications and resources: conversion programs, image display and analysis, surface and volume rendering, PACS clients and servers. Many programs are classified by a speciality to allow you to find similar programs by imaging modality, medical specialization, or similar. Half of all the programs listed here work with DICOM files, but there are over 25 file formats covered.

All the programs included are free and intended for distribution; there are no "demo" versions of commercial applications. If you are involved in programming, many of the programs are open-source, and provide APIs and SDKs for radiology programmers.